1. Field of the Invention
The present invention relates to a flat panel display device, and more particularly to a flat panel display device that is capable of compensating for a panel defect via a repair process and optimizing the data, which are to be displayed in the panel defect area, with a compensation value of a compensation circuit, and a picture quality controlling method thereof.
2. Description of the Related Art
Recently, various flat panel display devices with reduced weight and size, which have been a disadvantage of a cathode ray tube, are becoming more common. Flat panel display devices include liquid crystal display, field emission display, plasma display panel, organic light emitting diode, etc.
The flat panel display devices include a display panel for displaying a picture, but a panel defect may be found during a test process in such a display panel.
The picture quality defect appearing during the test process is mainly causingd during the manufacturing process. For example, the panel defect can be causingd by a deviation in an amount of exposure, the number difference of lens of an exposure machine, etc. in an overlapping exposure process. The panel defect causingd by the process deviation can be manifested as a fixed form such as dot, line, belt, circle, polygon, etc, as illustrated in FIG. 1 to 5, or as an undetermined form.
A repair process such as a thin film forming, a patterning process, etc., is carried out in order to recover the panel defect, but the panel defect recovered by the repair process is limited and the defective product may have to be disposed as a waste if the panel defect is too much. Further, in most cases, brightness or chromaticity in an area where there has been the panel defect appears different from a non-defect area even if the repair process is carried out.
The repair process for a pixel defect which appears as the dot shape in the panel defect mainly includes a method of making the defect pixel a dark spot. But, the created dark spot is almost not perceived in a black gray level as in FIG. 6A, but is clearly perceived as a dark spot in a display screen of a middle gray level and a white gray level, as in FIGS. 6B and 6C.
As a result, there is a limit in compensating a picture quality deterioration causingd by the panel defect with only the repair process of creating a dark spot for recovering the panel defect.